Adsum Sunflower

What was the brief?
To provide 25 units of deeply affordable and Net-Zero site energy ready permanent rental housing for the population served by Adsum House. The goal was to create a safe, vibrant community where its occupants could feel pride of ownership of their home. Another goal was to demonstrate that building to Net-Zero site energy could be possible within a tight budget and timeframe.

What were the key challenges?
Ensuring affordability and speed of delivery. The project was developed and built during the coronavirus pandemic and had tight funding timelines and construction budget from its major government funders.

What materials did you choose and why?
The buildings are wood-framed and were pre-panelized in a local NS plant to minimize waste and save time. Doors, windows, and mechanical equipment were locally sourced for shorter lead times and better future servicing. Exterior cladding and roofing were selected to meet the tight budget and client requirements for durability and maintenance. Flooring was a luxury wood-look vinyl plank for its non-slip, water resistance, and accessibility properties while providing a warm, residential feel.

Team:
Architect: Passive Design Solutions
Client: Adsum for Women and Children
Consultant: Affordable Housing Association of Nova Scotia
GC: Dora Construction
Panelization: Eastcut
Structural: Andrea Doncaster
Landscape: Clinton Pinks
Electrical Design: Equilibrium Engineering
Natural Playscape Design: Cobequid Consulting
Photo credits: Julian Parkinson

Material Used:
1. Facade cladding:
Horizontal and vertical vinyl siding, Mitten
Thermally modified wood siding, Thermory
Custom CNCed corten steel panels, Velocity Machining

2. Flooring: Luxury Vinyl Tile, Evolution Magma
3. Doors: Kohltech Exterior Doors
4. Windows: Kohltech Triple Glaze
5. Roofing: Asphalt shingle, IKO

See the original article in SABMag/Ontario FOCUS about this project.

The Sunflower is a 25-unit long-term rental housing development and community centre for Adsum for Women and Children, a local not-for-profit based in Halifax. The project was one of the recipients of the first round of Federal Rapid Housing Initiative funding in 2020.

Adsum is an organization leading change in housing through advocacy, support, and services to end homelessness. The goal of the Sunflower was to create 25 new units of rental housing for Adsum clients who were experiencing housing insecurity and need a safe, affordable and permanent place to call home.

The Sunflower was built on the site of a former school donated by Halifax Regional Municipality that Adsum had converted into transitional housing. The building was outdated and its layout far from ideal. Although initial explorations were made to save the existing building, the project team ultimately decided to demolish and make way for new housing.

The new building footprints were designed to make use of the existing brown site and driveway to minimize disturbance. The buildings were oriented for solar south to maximize solar gains and natural daylight, and their positioning close to Greenhead Road also allows for future expansion should Adsum opt to build more units.

The site design was based on the vision of creating a small pocket neighbourhood, and each unit entrance was designed to face onto a central courtyard to foster a sense of community and safety for the tenants, many of whom have experienced domestic violence.

The community centre—outfitted with offices, program space, accessible washrooms and laundry, and a communal kitchen—was placed closest to the road, providing a buffer for the private dwelling units while acting as a connection point for the staff and tenants.

The two-storey housing units are distributed among four separate buildings, creating a sense of openness and respecting the existing density and fabric of the neighbourhood. The unit mix consists of one, two and three-bedroom units in stacked and townhouse configurations, with four fully barrier-free units placed
closest to the community centre and parking.

A key design focus was to incorporate Passive House principles and to achieve Net-Zero—a must for the long-term financial sustainability of project given the below-market rents that were required through the funding model. By increasing the efficiency up-front through thoughtful design, reaching Net-Zero site energy became an attainable goal, and the resulting architectural design was able to address other vital client needs such as the creation of spaces that are light-filled, comfortable, buffered from outside noise, and resilient to storms.

The building envelope was designed for Passive House airtightness targets and detailed for elimination of thermal bridging. The energy modelling work was done iteratively throughout the design phases to achieve Net-Zero energy using only the available roof space for future PV modules, which informed the window layouts, insulation levels, and overhang shading.

The durability of exterior and interior finishes was critical to ensure that ongoing maintenance costs and efforts would be minimized, since Adsum operates on a tight budget focused on serving the needs of their tenants. Vinyl siding was used in varying orientations, along with thermally modified wood accents to add warmth and visual interest.

The environmental impact of material choices was considered in the specifications. Locally available building materials were prioritized, and high embodied carbon materials were used only as necessary. The structural design eliminated bearing in the demising walls and reduced frost wall thickness from 8” to 6” resulting in a 25% reduction in concrete use.

A simple roof structure was designed to bear the added weight of the planned PV system. No structural steel was used, the amount of glazing was balanced for egress, daylighting, ventilation, energy performance and embodied carbon, and no  formaldehydes were permitted in any interior finishes.

Locally manufactured triple-glazed vinyl windows were used throughout the project. Casement and awning sizes were kept compact to extend the lifespan of the
operable windows. Window sizes were balanced in the energy model and low solar heat gain glass was strategically used to reduce the cooling loads to a level where air conditioning was not required.

The heating system decision was complex—a ducted heat pump was cost-prohibitive, and single ductless mini splits in each unit were deemed too complicated to operate and maintain, so electric baseboards were chosen as the main heat source. Efficiencies were found by sharing heat pump hot water heating between one-bedroom units, and all appliances and plumbing fixtures were chosen based on a combination of energy efficiency, ease of use, and local availability. Centralized plumbing layouts, insulated water lines, and hot water heat pumps reduced hot water use by 75%, and low flow fixtures were specified to reduce overall water use.

Time was a critical factor throughout the project as the main federal funding source required that the project be substantially completed within a year of its inception. A collaborative and decisive design team was essential to bring the drawings from concept to construction documentation within six months. The Sunflower is now fully occupied and forms a key part of Adsum’s ongoing operations and long-term
housing strategy.

Working under an integrated team model, the project was successfully delivered during the coronavirus pandemic within just eighteen months—an achievement that we hope can help demonstrate what is possible in addressing both the current housing and climate crises.

Within such a tight, Passive House structure, outdoor air cannot penetrate the building’s thermal envelope; consequently manifesting an unhealthy living environment. The top-ported, HERO® Fresh Air Appliance was installed within each housing unit to bring fresh air in and exhaust stale air out while optimizing the energy required to do so, and keeping the design focus at Net-Zero.

MOLLY MERRIMAN NSAA, OAA, MARCH, PROJECT ARCHITECT, PARTNER AND NATALIE LEONARD P. ENG., CONSULTANT AND ENGINEER, FOUNDING PARTNER ARE WITH PASSIVE DESIGN SOLUTIONS.

Materials Used:

Facade cladding: Horizontal and vertical vinyl siding, Mitten
Thermally modified wood siding, Thermory
Custom CNCed corten steel panels, Velocity Machining
Flooring: Luxury Vinyl Tile, Evolution Magma
Doors: Kohltech Exterior Doors
Windows: Kohltech Triple Glaze
Roofing: Asphalt shingle, IKO